The present disclosure relates generally to payload recovery systems and methods.
Barcodes are a popular means for encoding information in printed matter; however, they are overt and often unsightly. If an image is to be a part of the composition of the printed label or page, a viable alternate to using a barcode is to hide information in the image. It has been found that information may be encoded in the halftone of an image, using techniques such as cluster-dot halftoning. The process takes any grayscale image and a payload of data to be encoded therein as input, and produces a bitonal clustered-dot halftone of that image with selected halftone clusters shifted to carry varying number of bits from the payload. The result is a data-bearing steganographic halftone (i.e., stegatone). The small size and large number of clustered-dot cells in printed halftones allow the printer/encoded bit density to be quite high, typically over 2000 bytes/square-inch. While this encoding process has been successful, suitable systems and methods for properly decoding data-bearing steganographic halftones at high payload densities are not readily available, due in part to alignment issues.